Locking device for bucket teeth



A. N. CRAWFORD 2,312,802

LOCKING DEVICE FOR BUCKET-TEETH March 2, 1.943.

, Filed Jan. 51, 1942 Patented Mar. 2, '1943 UNITED STATES PATEN'l orr cs LOCKING DEVICE FOR BUCKET TEETH Arthur N. Crawford, Foresthill, Calif.

Application January 81, 1942, Serial No. 429,0 4].

Claims.

This invention relates to bucket teeth for dredge buckets and the like, and particularly to a tooth unit which includes a base member per manently mounted on the bucket and a wearing point or tip removably mounted on'the base.

A major object of my-inventio'n is to provide a unit of the above general type having a removable element holding the members against separation, and which is'adapted' to be placed or removed from above'rather than from one side of the unit, as has heretofore been the case.

in turn is engaged by a removable key which prevents separation of the members of the tooth unit; the spring acting to take up any slackbetween the point and base, and also tending to prevent loosening of the key without the need of otherwise locking the same in place.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly efiective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as willfully appear by a perusal of the following specificationand claims.

In the drawing similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a sectional elevation of the unit, showing the parts thereof in adjacent but nonlocked relation.

Figure 2 is a fragmentary top plan view of the unit, showing the parts more widely separated than in Fig. 1.

Figure 3 is a side elevation of the unit, mainly in section, and showing the parts locked together.

Referring now-more particularly to the characters of reference on the drawing, the base member of the unit comprises a body I substantially rectangular in cross section and adapted at its rear end to be rigidly secured on and project from the forward edge of a dredge bucket or the like in the conventional manner.

Also formed with the base integral with the body is a tongue 2 of somewhat lesser height and the base member at the junction of the tongue and body, the topmost transverse shoulder 8 being set back some distance from the side and bottom shoulders 3a as shown.

Cut into the top of the tongue centrally between its sides is a relatively large and deep groove 4 of rectangular form, which extends from a point some distance ahead of the top shoulder 3 to a rearward termination some distance rearwardly of said top shoulder. The groove does not cut through the metal of the shoulder, so that the rear end portion of the groove forms a socket 5 covered by a lip 6 on the body, as plainly shown in Fig. 1.

, Also cut through the tongue vertically from the bottom of the groove at its front end is a keyway I, which is of tapering form in the longitudinal plane of the tongue and disposed substantially at right angles to the upper face of the tongue. This keyway is'somewhat narrower than the groove and at the bottom is enlarged lengthwise of the tongue, as shown at 8 fora purpose which will be seen later. Also, the keyway is positioned 'so that its forward edge at the bottom is rearwardly of the bottom transverse shoulder 3a.

The removable point comprises a heavy, platelike blade 9 of rectangular form in plan and which extends the full width of the body and at its rear end is adapted to substantially abut against the top body shoulder 3 for its full width. Depending from and rigid with the blade is a socket lil open to the rear, shaped to receive and fit the tongue, and disposed with its rear edges ahead of the rear edge of the blade, or in position to substantially engage the shoulders 3a when the blade is engaged with shoulder 3. The blade has a key slot ll cut therethrough to register with the keyway when the parts are in a fully assembled position.

The blade at its rear end is formed with a rear? wardly projecting retaining tongue I2 disposed in depending relation to the blade and of a size and position to enter the socket 5. The forward end of the tongue 12 is formed with a downward slope to the rear and is adapted to be engaged by the similarly sloping rear end of a locking pawl l3 slidable in the groove 4. This pawl is formed with a forwardly projecting stem It about which a relatively heavy compression spring I5 is disposed, this spring projecting ahead of the stem and being covered at its forward end by a rounded cap it. The total length of the pawl, spring and cap when the. spring is expanded or slack, relative to the length of the groove from its front front end of the groove, there is ample space rearwardly of the pawl for the free entry of the tongue l2 into said groove, as shown in Fig. 1.

I The bevel or slope of the retaining tongue and pawl not only provides for a connection of substantial area between said tongue and the blade without excessive retractive movement of the pawl, but causes an upward and rearward pressure to be asserted by the pawl against said tongue when the spring is compressed, tending to'firmiy bind the point against possible looseness.

When connecting the point and base together, the pawl is first-retracted as described, and the blade is slid along the tongue 2 in initially tilted relation thereto, until the tongue I 2 is disposed in the groove 4 rearwardly of the pawl. The tapering form of the tongue 2 and its socket allow of the initial entry of the tongue into said hanging lip 6, and the slot ll registers with or exposes the upper end of the keyway I. The pawl is then covered by the blade, but the cap Ii is then exposed through the slot II and canbe easily advanced so that the pawl will engage the tongue l2. When such engagement is effected, the cap still projects some distance into the keyway and so is in the path of a taper key or drift II which is then driven into the keyway through the slot I i.

The forward edge of the keyway has a rearward slope relative to the groove so that the driving of the key, which engages the cap it, shifts the latter rearwardly. As soon as a snug engagement of the pawl with the tongue I2 is dbtained with such shifting, further driving of the key compresses the spring i5 until cap it engages stem l4 and thus relieving the spring of driving pressure-during the final movement of the pawl into locking position. If, during subsequent digging operations, the tooth should become loose on tongue 2, the strong spring being already compressed will exert sumcient force to advance the pawl against tongue I2 so as to take up all lost motion.

In order to prevent the key from possibly slipping, its rear edge is notched as at i8 to fit the cap i 6, said notch being positioned along the key so as to engage the cap-when the key is fully driven. If an additional holding or retaining of the key is thought necessary, its lower end may 8 of the keyway. The key slot il in the blade 9 is of suiiicient extent lengthwise of the unit so that the key never binds against the blade to interfere with the rearward movement of the point.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I.

claim as new and useful and desire to secure by Letters Patent is; s

1. In a two-part digger tooth, one part-comprising a body adapted to be mounted on and project from a digger, and a tongue projecting forwardly from the body; and a separate point comprisinga forwardly projecting blade member and a depending rearwardly open socket member to receive the tongue; a retaining tongue projecting rearwardly from the blade. the body having a forwardly facing socket at its forward end to receive the retaining tongue, the first-named tongue having a keyway therethrough from top to bottom and the blade having a key slot registering with the keyway when the retaining tongue is in the socket, and a key adapted to be removably driven through the slot and keyway; said keyway being disposed at a downward slope to the rear so that its lower end is rearwardly oi the rear end of said tongue whereby the key will clear the socket member without cutting through the latter.

2. In a two-part digger tooth, one part comprising a body adapted to be mounted on and project from a digger, and a tongue projecting forwardly from the body: and a separate point comprising a forwardly projecting blade member and a depending rearwardly open socket member to receive the tongue; a retaining tongue projecting rearwardly from the blade, the body having a forwardly facing socket at its forward end to receive the retaining tongue, the first-named tongue having a keyway therethrough ahead of the socket and said separate part having a key slot registering with the keyway when the retaining tongue is in the socket, a key adapted to be removably driven through the slot and keyway, and means movably mounted on the body between the key and retaining tongue and spring pressed against such tongue by and upon driving of the key.

- 3. In a two-part digger tooth, one part comprising a body adapted to be mounted on and project from a digger, and a tongue projecting forwardly from the body; and a separate point comprising a forwardly projecting blade member and a depending rearwardly open socket member to receive the tongue; a retaining tongue projecting rearwardly from the blade, the body having a forwardly facing socket at its forward end to rehaving a keyway therethrough ahead of the socket and said separate part having a key slot regis-' tering with the keyway when the retaining tongue is in the socket, a key adapted to be removably driven through the slot and keyway, and a longitudinally compressible unit mounted on the body between and engaging the key and retaining tongue, said unit being compressed by the key upon driving of the latter whereby to exert a yieldable holding pressure against the retaining tongue.

4. In a two-part digger tooth, one part comprising a body adapted to be mounted on and project from a digger, and a tongue projecting forwardly from the body; and a separate point comprising a forwardly projecting blade member and a depending rearwardly open socket member to receive the tongue; a retaining tongue projecting rearwardly from the blade and depending therefrom, the first named tongue having a longitudinal groove in its upper face toslidably receive the retaining tongue and said groove terminating at its rear end in a socket to receive such tongue,

ject from a digger, and a tongue projecting tor wardiy from the body; and a separate point comprising a forwardly projecting blade member and depending rearwardly open socket member to receive the tongue; a retaining tongue projecting rearwardly from the blade and depending therefrom, the first named tongue having a. longitudinal groove in its upper face to slidably receive the retaining tongue and said groove terminating at its rear end in a socket to receive such tongue, a keyway cut through the first named tongue from the bottom of the groove adjacent its forward end, the blade having a key slot to expose the upper end of the keyway when the retaining tongue is in the socket, a key adapted to be driven through the keyway, and a longitudinally compressible unit slidable in the groove between the retaining tongue and the keyway and engaging such tongue and the rear edge of the key and being compressed by said key when the latter is fully driven.

6. A structure as in claim 4, in which the forward end of the unit is rounded; the rear edge of f the key having a notch to fit over said rounded end of the unit and positioned to engage the same when the key is fully driven.

7. A structure as in claim 4, in which the length of the unit relative to that of the groove ahead of the socket and the retaining tongue is such as to enable said tongue to enter the groove before passing into the socket upon retractive movement of the unit away from the socket.

8. A structure as in claim 5, in which said unit comprises a tongue engaging pawl and a compression spring in front of the pawl.

9. A structure as in claim 5, in which said unit comprises a tongue engag n pawl, a stem projecting forwardly from the pawl, a compression spring about the stem projectin ahead of the.

same and a key engaging cap on the forward end of the spring.

10. A structure as in claim 4, in which said unit includes a pawl to engage the retaining tongue; the forward edge of such tongue being cut on a downward slope to the rear and the rear edge of the pawl being cut with a matching slope.

- ARTHUR N. CRAWFORD. 

